Non-toxic salts of j



NOV- 5 1963 G. NOMINE ETAL 3,109,857

NoN-'roxc sAL'rs oF 3,5-DsuLFAM1NoBENzo1c ACID AND A PROCESS FOR THEIR PREPARATION Filed Feb. 1a, 1960 ZVVENZ'ORS GERAR NOM/NE MICHEL VGNAU /I-UC/EN PENASE HM# W ATTORNEYS.

United States Patent NN-TGXC SALTS QF 3,5-BlSUiJFAh/NQBEN- ZC ACE) AND A PRCESS FR 'EHR PREPARATlGN Gerard Nomine, Noisy-le-Sec, Michel Vigneti, Neuilly sur-Seine, and Lucien Penasse, Paris, France, asignors to Roussel-UCLAF, Societe Anonyme, ilaria,

France, a corporation of France Filed vFel). i8, i969, Ser. No. 9,5?1 Claims priority, appiication France Fein. 27, 1959 9 Claims. (Cl. Zen-SG1) This invention relates to a disulfamino substituted acid and its salts and a process for their preparation. More particularly, it relates to 3,5-disulfaminobenzoic acid as well 1as to its non-toxic mineral and organic salts.

The 3,4-disulfamino-benzoic acid and its non-toxic salts possess important anti-inflammatory properties.

l CHaC-CHz-C The invention has for its object the obtention of 3,5-disulfamino-benzoic acid and its non-toxic salts.

Another object of the invention is the development of a method for the preparation of 3,5-disulfarnino-bcnzoic acid :and its non-toxic salts in a high degree of purity with good yields.

.These and other objects of the invention will become more apparent as the description proceeds.

We have found, and this represents our invention the new and novel chemical compounds, 3,5-disulfaminobenzoic acid and its non-toxic salts. 3,5-disulfarninobenzoic acid and its non-toxic salts, especially the mineral and organic salts may be represented by the following general structural formula wherein R1 and R2 are selected from the group consisting of hydrogen, a non-toxic metallic radical and Va non-toxic organic basic radical; with the proviso that when R1 represents a non-toxic metallic radical or a non-toxic organic basic radical, R1 and R2 are identical.

.The FIGURE shows a curve demonstrating anti-inflammatory action or trisodium disulfamino-henzoate.

The products according to the invention are obtained by reacting pyridinium sulfonic acid with 3,5-diaminobenzoic acid or its salts. The 3,5-disulfamino-hcnzoic acid thus formed is isolated by formation of an insoluble intermediate organic salt which is finally transformed into the desired salt in accordance with known methods.

In accordance `with a preferred embodiment for the preparation of the products of the invention, chlorosulfonic acid is added to pyridine at a temperature in the neighborhood of 0 C. and preferably Ibelow 0 C. 3,5- diamino-benzoic acid in solution in pyridine or 3,5-diamino-benzoic acid hydrochloride in `solution in a mixture of pyridine and dimethylformamide is added to the mixture of pyridinium sulfonic acid and pyridine .at temperatures below room temperature and the oily phase is decanted. The 3,5-disulfanino-benzoic acid is isolated in the form of an insoluble sal-t with a high molecular weight quaternary ammonium compound such as benzyldimethyl 2 [2 (p-l-l,3,3tetrarnethylbutyl-phenoxy)- ethoXy] -ethyl ammonium chloride, hereinafter referred to by its commercial name Hyamine 1622. 'This insoluble salt is transformed into the triethylarnine salt or into any l l lQ-ooni-onzoone-CHT-rlt-om( o1- "ice other non-toxic organic or mineral salt according to known methods.

It the direct isolation of 3,5-disulfamino-benzoic acid is attempted, very great diculties are encountered in separating `the pure substance from the sulfonation mixture. The preparation of the intermediate insoluble highmolecular weight Quaternary ammonium salt makes it possible to overcome these difculties, which was entirely unexpected, and this is one of the most characteristic features of the process according to the invention. In addition to commercial Hyarnine 1622, which is also known under the name of :phemerol chloride or benzetho nium chloride and has the empirical formula C27H42C1NO2 H2O and the structural formula C Ha C Es H2O other high-molecular weight quaternary ammonium compounds capable of producing a water-insoluble salt by double decomposition may be used. Such compounds are, for example, Hyamine 2389 described in the index of Modern Sulfonated Oils and Deter-gehts `(vol. Il) by l. P. Sisley, page 373 as being the chloride of a Quaternary ammonium base, Cequartyl BE described on page 287 of the above mentioned Index 4as being based on ammonium salts, Arquad 2C which, according to the same Index on page 261 is said to be dilauryl dimethyl ammonium chloride, and Zephirol which, according to `the same Index on page 286 is said to be an `alkyl dimethyl benzyl ammonium chloride.

If a non-toxic mineral salt of 3,5-disulfaminohenzoic acid is desired, it may advantageously be `obtained from the triethylamine salt yby double decomposition of the latter With an appropriate salt or also by displacement with a base. Thus, depending upon the selected mode of operation, it is possible to preferentially neutralize the two sulfamino radicals or the latter two as well `as the carboxylic acid radical which is more diflicult to neutralize.

As examples of non-toxic mineral salts can be mentioned the ammonium salt, the alkali metal salts, the alkaline earth salts, the non-toxic metallic salts with metals of the iron series, etc. Preferable are the trisodium salt of 3,5-disulfamino-benzoic acid, the tripotassiurn salt of 3,5disulfamino-henzoic acid, the disodium salt of 3,5-disulfamino-benzoic acid.

As examples of nontoxic organic salts can he mentioned the trialkylamine salts such as the di-(triethylamine) salt of 3,5-disulfamino-henzoic acid, ythe monoand di-alkylarnine salts, etc.

As a variation of the process according to the invention, it is also possible `to prepare the 3,5-disulfamino-benzoic acid as well as its salts by applying the Piria reaction to 3,5-dinitro benzoic acid. In order to accomplish this, the 3,5-dinitrobenzoic acid is treated with a mixed aqueous solution of sodium suliite and sodium bisulte and the 3,5-disulfamino-benzoic acid is isolated in the form of its H3/amine 1622 salt. ln this case the yields are lower than the yields obtained by sulfonation of 3,5-daminobenzoic acid.

The following examples Will serve to make the process of the invention more readily understood.

The examples are non-limiting. An entirely equivalent technique known to those skilled in the art may be employed Without departing from the scope of the invention. ln this manner, other solvents may be employed, the order of addition of reactants4 may be varied and the conditions of temperature and pressure may be varied.

V3 (3 EXAMPLE I Preparation of 3,5-Dislflfonmi'zo-Beizoic Acid and its Trisoiz'ium Saiz* (a.) 3,-DISULFAMINO-BENZOATE OF DI-(TRIETHYL- AMINE) 575 ce. of pyridine are cooled toa temperature below C. in an atmosphere of nitrogen, and then 57.5 cc. of chlorosulfonic acid are add-ed over a period of 1 hour. The temperature of the mixture containing the pyridinium sulfonic acid thus prepared is raised to +5 C. and then a solution of 50 gm. of 3,5-diamino-benzoic acid hydrochloride in 100 cc. of dimethylforrnamide and 200 cc. of pyridine are added over a period of 25 minutes. The mixture is agitated for 30 minutes, the oily phase is decanted and Washed iirst with pyridine and then with ether, after having added water, and again with ether. Finally 3800 cc. of a aqueous soution of Hyamine 1622 hydrochloride are added over a period of. 1 hour while stirring. I'i`he reaction mixture is Vacuum filtered, the iilter cake is washed by resuspending it in 2 liters of water and again vacuum ltering the suspension. The iilter cali! is dissolved in 1 liter of ethanol and the solution is evaporated to dryness in vacuo. The residue is taken up in 1750 cc. of butyl acetate. M1 of the solvent is distilled 0H, 50 cc. of ethanol are added and then a mixture consisting of 1250 cc. of butyl acetate, 375 cc. of acetic acid Vand 375 cc. of triethylarnine is added. The mixture is cooled with ice overnight, lltered, the filter caire is washed twice with 50 cc. aliquots of butyl acetate and then with 50 cc. of ethyl acetate. It is then dried in vacuo at 60 C. There is obtained 89 gm. of the crystallized acid di- (triethylamine) salt of 3,5-disulamino-benzoic acid having a melting point of 236 C. The yield is 78% of theory.

This product has not previously been described.

A1zaZysis.-C19H38O8N4S2; molecular weight=514.65. Calculated: C, 44.34%; H, 7.44%;N, 10.89%; S, 12.46%. Found: C, 44.3%; H, 7.4%; N, 10.4%; S, 12.6%.

(b) SODIUM s,-DISULFAMINGBENZOATE 2.27 gm. of trietliylamine 3,5-disulfamino-benzoate prepared according to (a) above, are dissolved in 47 cc. of methanol. hydroxide in 13 cc. methanol is slowly added thereto. The mixture is allowed to stand for 48 hours at room temperature. It is then vacuum filtered, the filter cake is washed 4 times with 5 cc. aliquots of methanol and is dried in vacuo at 150 C. 1.56 gm. (93% of theory) of the crystallized trisodium salt of 3,5-disulfamino-benzoic acid are obtained thereby.

This product is new.

AnaIysis.-C7H5O3N2S2Na3. Calculated: C, 22.22%; H, 1.33%; N, 7.40%; S, 16.95%; Na, 18.24%. Found: C, 22.5%; H, 1.6%; N, 7.3%; S, 16.6%; Na, 17.9%.

EXAMPLE H Preparation of the Tripozassium Soit of 3,5-Disuifamin0- Beitzoic Acid A solution of 800 mgm. of pelletized sodiumv i XAMPLE lil Preparation of the Acid Disodiifm Sal of 3,5-Disulfamin0- Benzoic Acid A solution of sodium acetate in methanol is added to a solution of the acid di-(triethylamine) salt of 3,5-disu famino-benzoic acid in methanol. The crystallized disedium salt is separated by Vacuum ltration and dried and is obtained tiiereby with a quantitative yield.

.Analysis- Sulfuric ash: Calculated: 39.87%. 40%.

As a comparison, we will now give the mode of operation for the preparation of the Hyamine 1622 salt of 3,5-disulfarnino-benzoic acid by the method of Piria, starting with 3,5-dinitrobenzoic acid.

EXAMPLE 1V Preparation of the Hyamine 1622 Sail of 3,5-Disin' amiiw-Befzzoic Acid by the Ii/lethod of Pii'ia l0 ce. of soda iye are added to 90 cc. of a concentrated solution of sodium bisulte containing 481 gm. of sodium bisulte per liter, and then 25 cc. of 2 N sodium hydroxide, 200 cc. of distilled water and 10.6 gm. of 3,5-dinitrobenzoic acid are added. The mixture is heated to the boiling7 point in an atmosphere of nitrogen, while stirring and heating is continued for 50 minutes. The reaction mixture is cooled and 750 cc. of a 10% solution of Hyamine 1622 are added. The mixture isk allowed to stand for 4 hours and then vacuum ltered. lThe lter cake is washed with iced water and dissolved in cc. of methylene chloride. The organic solution is washed with water, dried over sodium sulfate and evaporated to dryness in vacuo. The Hyamine 1622 salt of 3,5-disulamino-benzoic acid is obtained thereby. This salt behaves in similar fashion to that obtained in Example I during its transformation into the triethylamine salt; however, it is obtained in less favorable yields.

.EXAMPLE V Demonstration of the Anti-Inflammatory Action of the Trisodiiim Salt of 3,5-Diszllfamino-Benzoic Acid In order to demons-trate the anti-inflammatory action of the non-toxic salts or" 3,5-disulfaminobenzoic acid, trisodium 3,5-disu`ifamino-benzoate (R1003) produced according to Example I was tested on rats which were in an -arthritic condition induced with croton oil (an adaptation of a technique of '.Selye) 24 young male rats weighing approximately 100 gm. each, of which 12 were normal and 12 were surrenalectomined, were divided into four groups of six rats each. A11 oi the rats received an injection of 0.1 cc. or" dilute Groton oil implanted under the aponeurosis, both on day 0 and day 2.

`In addition, the four groups received the following treatments:

(1) Normal controls: physiological serum, 2 cc./kg./ day, subcutaneously.

(2) Normal rats: Rl003, 100 mgm./kg./day, subcutaneously.

(3) Surrenaleotomized controls: physiological serum, 2 cc./kg./ day, subcutaneously.

(4) Surrenalectomized rats: R1003, 100 mgm./kg./ day, `subcutaneously in ve daily injections (from day 0 to day 4, inclusive).

The average diameter of the tibiotarsal joint is determined on day 0, 2, 3 and 4 by means of a slide caliper.

The results are expressed in tenus of the average increase of this diameter with reference to day 0 and are shown in Kthe figure.

The changes in the diameter of the joint in the four groups of rats are shown in the figure. The higher arthritic reaction in the surrenalectomized rats is normal. The degree of protection obtained with R1003 is of the same order in the surrenalectomized rats as in the normal rats. In both cases it should be noted that there is Found a good degree of protection (45%) `on day 2, that is, during the actute phase of the inilammation (this measurement was made two hours after the Iinjection of croton oil).

In a test of the acute toxicity by intraperitoneal injection on mice the compound R1003 has been found to be devoid of any ,toxicity up to a dose of 1 gm./kg.

It can thus be seen that at a dose of 100 mgmjkg., the trisodium salt of 3,5-disulfamino-benzoic acid exhibits a great anti-inaurmatory action in rats, While it is devoid of any toxic properties in mice up to a dose of 1 gin/kg.

The preceding examples were given purely for descriptive purposes. Such changes and modications as would occur to one skilled in the art may be made Without departing from the spirit of the invention. These and various other changes may be made without departing from the spirit of the invention or vthe scope of the appended claims.

We claim:

1. A 3,5-disulfamino-benzoic acid compound having the structural formula wherein R1 and R2 are selected from the group consisting of hydrogen and a non-toxic basic radical selected from the group consisting of ammonium, alkali metal, alkaline earth metal, trialkyl ammonium, dialkyl ammonium and monoalkyl ammonium, with the proviso `that when R1 represents said non-toxic basic radical selected from the group consisting of ammonium, alkali metal, alkaline earth metal, triallryl ammonium, dialkyl ammonium and mono'alliyl ammonium, R1 and R2 are identical.

2. The acid di-(triethylamine) salt of 3,5-disulfaminobenzoic acid.

3. The disodium salt of 3,5-disulfamino-benzoic acid.

4. The trisodium salt of 3,5-disulfamino-benzoic acid.

5. The tripotassium salt of 3,5-disulfamino-benzoic acid.

6. The benzyl dimethyl 2 [2 (p 1,1,3,3 `tetramethyl butyl phenoxy) ethoxy] ethyl ammonium salt of 3,5-disulfamino-benzoic acid.

7. The process of preparing a Water-insoluble, highmolecular Weight quaternary ammonium salt of 3,5-disulfamino-benzoic acid which comprises the steps of adding chlorosulfonic acid to pyridine at a temperature of about 0 C., adding the hydrochloride of 3,5-diaminobenzoic acid in solution in an inert organic solvent at a temperature below room temperature, separating the oily phase, mixing the said oily phase with an aqueous solution of a high-molecular Weight quaternary ammonium compound capable of producing a Water-insoluble salt with 3,5-disulfamno-benzoic acid by double decomposition and separating the said water-insoluble salt of 3,5-disulfamino-benzoic acid.

8. The process of claim 7, wherein the `said high-molecular weight quaternary ammonium salt of 3,5-disulfamino-benzoic acid is reacted with a compound selected from the group consisting of trialkylamine, dialkylamine and monoalkyl amine to form a compound selected from the group consisting of the corresponding acid diammonium 3,5-sulfamino benzoate and the corresponding triammonium 3,5-disulfamino-benzoate.

9. The process of claim 8 wherein the said ammonium 3,5-disulfamino benzoate formed is reacted with a compound selected from the group consisting of an alkali metal salt and an alkaline earth metal salt to form the corresponding metal salt of 3,5-disulfamino-benzoic acid.

References Cited in the le of this patent UNITED STATES PATENTS 2,212,171 Salzberg Aug. 20, 1940 2,271,707 Munz et al. Feb. 3, 1942 2,527,810 Goldberg et al Oct. 31, 1950 2,785,195 Beck et al. Mar. 12, 1957 2,789,132 Surreau et al. Apr. 16, 1957 2,836,620 Bersworth et al. May 27, 1958 FOREIGN PATENTS 372,389 Great Britain Apr. 28, 1932 OTHER REFERENCES Weil et al.: Ber. Deut. Chem., vol. 55, pages 732-737 (1922).

Weil et al.: Ber. Deut. Chem., vol. 55, pages 2533-2542 (1922).

Butler et al.: J.A.C.S., vol. 6l, pages 914-915 y(1939).

Holmes et al.: American Chemical Journal, volume 13, pages 371-384 (1891). 

1. A 3,5-DISULFAMINO-BENZOIC ACID COMPOUND HAVING THE STRUCTURAL FORMULA 1-(R1-OOC-),3,5-DI(R2-SO3-NH-)-BENZENE WHEREIN R1 AND R2 ARE SELECTED FROM THE GROUP CONSISTING OF HYDROGEN AND A NON-TOXIC BASIC RADICAL SELECTED FROM THE GROUP CONSISTING OF AMMONIUM, ALKALI METAL, ALKALINE EARTH METAL, TRIALKYL AMMONIUM, DIALKYL AMMONIUM AND MONOALKYL AMMONIUM, WITH THE PROVISO THAT WHEN R1 REPRESENTS SAID NON-TOXIC BASIC RADICAL SELECTED FROM THE GROUP CONSISTING OF AMMONIUM, ALKALI METAL, ALKALINE EARTH METAL, TRIALKYL AMMONIUM, DIALKYL AMMONIUM AND MONOALKYL AMMONIUM, R1 AND R2 ARE IDENTICAL
 7. THE PROCESS OF PREPARING A WATER-INSOLUBLE, HIGHMOLECULAR WEIGHT QUATERNARY AMMONIUM SALT OF 3,5-DISULFAMINO-BENZOIC ACID WHICH COMPRISES THE STEPS OF ADDING CHLOROSULFONIC ACID TO PYRIDINE AT A TEMPERATURE OF ABOUT 0*C., ADDING THE HYDROCHLORIDE OF 3,5-DIAMINOBENZOIC ACID IN SOLUTION IN AN INERT ORGANIC SOLVENT AT A TEMPERATURE BELOW ROOM TEMPERATURE, SEPARATING THE OILY PHASE, MIXING THE SAID OILY PHASE WITH AN AQUEOUS SOLUTION OF A HIGH-MOLECULAR WEIGHT QUATERNARY AMMONIUM COMPOUND CAPABLE OF PRODUCING A WATER-INSOLUBLE SALT WITH 3,5-DISULFAMINO-BENZOIC ACID BY DOUBLE DECOMPOSITION AND SEPARATING THE SAID WATER-INSOLUBLE SALT OF 3,5-DISULFAMINO-BENZOIC ACID. 